Day 52: Arithmetic Sequences

In Algebra I use Dan’s Super Stairs to introduce Arithmetic Sequences. I used this same activity in Geometry which can be found on Day 15 and wrote about how I work Three-Act problems here.

The highlight of the day was when two students from two different periods recognized the rule n(n+1) in a way that I was not expecting…

Most students used a form of arithmetic sequence to add 1+2+3+4+…+21 then doubled it. When I asked for the total students for 1,000 stairs this method came up short and directed them towards different solution options.